{Someone who just sits down and posts instead of waiting for the blinds to come around, especially at 6max, is usually indicative of a fish. Ergo, my raise here on the button was to isolate the bad player and get heads up with him.}

Flop: ($6) 6♣8♥K♣
(2 players)
MP checks, Hero bets $4, MP calls $4

{Iso raise worked, and I flopped the second nut flush draw. In other words, I'm going to semi-bluff 100% of the time here. His flat call means he could have a flush draw, too, plus lots of pairs and A-type hands. The A♣ is definitely in his range, too.}

Turn: ($14) A♣
(2 players)
MP checks, Hero checks

{Well, the A♣ isn't in his range anymore! In fact, now I'm mostly concerned he's going to go away if I bet. Dunno if checking here is the best play or not, but it may be close either way; i.e.., it's EV neutral if I bet vs. checking behind. Dunno.}

River: ($14) 8♣
(2 players)
MP bets $0.50, Hero calls $0.50

{This is horrible poker on my part. Ugh. I lost track of my initial fish read on this guy. There are tons of worse hands in his range that will call a raise here. Almost any club or two pair-type hands will be hard for a fish to lay down. If he's got me beat, he's going to reraise. I woulda/coulda/shoulda raised him to something like $8 or so. This leaves me room to fold if he repops, but gets me paid off by many of his weaker made hands. This technique is called raise/folding, and it's definitely the right river play here. Instead I wimped out and just called behind because the board had paired and there was one better flush he could have had. Dumb, dumb, dumb.}